How do I disabled line breaks being added after images?

I’ve got an image tag and I can’t for the life of me figure out how to keep wordpress from auto-adding a line break right after the image code.

I’m using the plain text editor and I have the next bit of text right after the image (no line break). Like so:

<img src="http://example.com/wp-content/uploads/2008/05/image.jpg" alt="" title="image" width="200" height="115" class="alignleft size-full wp-image-15" /><h3><a href="http://example.com">Link</a></h3>

But when it shows up on the blog, it has the code like this:
<img src="http://example.com/wp-content/uploads/2008/05/image.jpg" alt="" title="image" width="200" height="115" class="alignleft size-full wp-image-15" /><br /><h3><a href="http://example.com">Link</a></h3>

(Note the addition of the <br /> tag afer the image tag and before the h3 tag)

Any ideas?